Green energy sources have grown in importance over the last decade. Moreover, controlling the release of greenhouse gases, such as carbon dioxide, while still producing affordable and sustainable energy has become vitally important. Not only has an effort to reduce such emission been pushed to the forefront of modern research because of concerns over climate change, but has also become increasingly significant to industrial companies operating under heavy regulatory pressure. Indeed, many Western governments continue to pass increasingly more stringent regulations that effect companies that produce potentially harmful emissions (i.e. cap-and-trade). Thus, a need has emerged for economically viable methods to reduce harmful greenhouse gas emissions.
In particular, power plants that burn organic fuels such as coal, natural gas, wood, biomass, or oil emit carbon dioxide (CO2) and other harmful pollutants into the atmosphere during operation. Commonly used non-organic technologies to reduce these emissions are costly, inefficient, and not 100% effective. While organic emission reducing technologies can also be used, currently available technology has lacked the efficiency to gain commercial popularity. For example, microalgae naturally may be used to convert CO2 into oxygen (O2). However, microalgae cultivation systems designed to reduce flue gas emissions generally lack the efficiency to be considered commercially viable. Moreover, incorporating such technologies into power plant operations adds cost with little benefit to the company, other than adhering to regulations. While microalgae can produce lipid-based oils, or bio-oils, as a byproduct creating a potential supplemental energy or revenue source for the company, currently available technology is incapable of producing sufficient levels of this biofuel to make the solution economically viable.
Recently, “lipid triggers” have been discovered that can dramatically boost bio-oil creation efficiency in microalgae. This discovery has made possible the prospect of sufficiently efficient, economical, and commercially viable flue gas emission reduction. In turn, a developing commercial need has emerged for a microalgae growing system and process that incorporates lipid trigger technology and that is capable of efficiently and economically reducing harmful flue gas emissions while producing sufficient levels of bio-oil in return.
Power plants use heat exchangers to reduce the heat of the flue gas. At older power plants the starting temperature post combustion of fuel may exceed 400 degrees Celsius. At newer plants that have a combined heat and steam turbine system, heat exchange temperatures may still exceed 200 degrees Celsius.